Technical Summary
Wireless, low power field devices enable industrial users to
significantly increase the amount of information collected and the number
of control points that can be remotely managed. The deployment of these
wireless devices will significantly improve the productivity and safety of
the plants while increasing the efficiency of the plant workers by
extending the information set available from wired systems. In an
industrial environment, low power, high reliability, and easy installation
and maintenance are mandatory qualities for wireless devices. The aim of
this document is to analyze the requirements for the routing protocol used
for Low power and Lossy Networks (LLN) in industrial environments. IPv6 is
perceived as a key technology to provide the scalability and
interoperability that are required in that space and is being more and
more present in standards and products under development and early
deployments.
Cable is perceived as a more proven, safer techhnology, and existing,
operational deployments are very stable in time. For these reasons, it is
not expected that wireless will replace wire in any foreseeable future;
the consensus in the industrial space is rather that wireless will
tremendously augment the scope and benefits of automation by enabling the
control of devices that were not connected in the past for reasons of cost
and/or deployment complexities. But for LLN to be adopted in the
industrial environment, the wireless network needs to have three
qualities: low power, high reliability, and easy installation and
maintenance. The routing protocol used for low power and lossy networks
(LLN) is important to fulfilling these goals.
Industrial automation is segmented into two distinct application spaces,
known as "process" or "process control" and "discrete manufacturing" or
"factory automation". In industrial process control, the product is
typically a fluid (oil, gas, chemicals ...).
In factory automation or discrete manufacturing, the products are
individual elements (screws, cars, dolls). While there is some overlap of
products and systems between these two segments, they are surprisingly
separate communities. The specifications targeting industrial process
control tend to have more tolerance for network latency than what is
needed for factory automation.
Irrespective of this different 'process' and 'discrete' plant nature both
plant types will have similar needs for automating the collection of data
that used to be collected manually, or was not collected before. Examples
are wireless sensors that report the state of a fuse, report the state of
a luminary, HVAC status, report vibration levels on pumps, report
man-down, and so on.
Other novel application arenas that equally apply to both 'process' and
'discrete' involve mobile sensors that roam in and out of plants, such as
active sensor tags on containers or vehicles.
Some if not all of these applications will need to be served by the same
low power and lossy wireless network technology. This may mean several
disconnected, autonomous LLN networks connecting to multiple hosts, but
sharing the same ether. Interconnecting such networks, if only to
supervise channel and priority allocations, or to fully synchronize, or to
share path capacity within a set of physical network components may be
desired, or may not be desired for practical reasons, such as e.g. cyber
security concerns in relation to plant safety and integrity.
All application spaces desire battery operated networks of hundreds of
sensors and actuators communicating with LLN access points. In an oil
refinery, the total number of devices might exceed one million, but the
devices will be clustered into smaller networks that in most cases
interconnect and report to an existing plant network infrastructure.
Working Group Summary
No controversy.
Document Quality
The I-D is informational and specifies IPv6 routing requirements.
Personnel
Who is the Document Shepherd for this document?
JP Vasseur (jvasseur@cisco.com)
Who is the Responsible Area Director?
Adrian Farrel (adrian.farrel@huawei.com)